MEXICO CITY (AP) — Vice President Joe Biden said Monday that Mexico’s three main presidential candidates share a vision of continued close cooperation with Washington, and used his brief visit south of the border to also knock down talk of drug legalization in the region.

Biden’s two-day trip to Mexico and Honduras comes amid calls by many of the region’s leaders to discuss decriminalizing drugs as a way to ease a vicious war on cartels that has left Latin America bloodied.

“It’s worth discussing, but there is no possibility the Obama/Biden administration will change its policy on (drug) legalization,” he said after meeting with President Felipe Calderon.

But the main purpose of his visit was to meet with the contenders in Mexico’s July 1 presidential elections to get a feel for future U.S.-Mexico relations.

The U.S. has enjoyed an unprecedented level of cooperation with Calderon, whose administration has received hundreds of millions of dollars to wage a heavily militarized fight against drug cartels. Drug-related violence has killed at least 47,515 people in Mexico from December 2006, when Calderon launched his first anti-cartel offensive, through September 2011.

Biden met Monday with Enrique Pena Nieto of the Institutional Revolution Party; Josefina Vazquez Mota of the ruling National Action Party; and Andres Manuel Lopez Obrador of the left-leaning Democratic Revolution Party. Calderon is not allowed to run again.

Recent polls show a tightening race with Pena Nieto ahead, followed by Vazquez Mota and Lopez Obrador.

When asked whether he had sensed any significant differences among the candidates with regards to cooperation with the United States, Biden answered simply, “No.”

“I’m not being flip, but no,” he said, before leaving a brief and unscheduled press conference at the end of a day of meetings.

Calderon’s allies have accused Pena Nieto’s PRI party of maintaining ties to drug-traffickers and wanting to relent in the fight against cartels.

Pena Nieto said he told Biden that the PRI, which ruled Mexico for more than 70 years before being ousted by the PAN, is committed to the fight against organized crime.

“The discussion is not whether we should or shouldn’t fight against it but what we can do to achieve better results,” he told reporters.

Vazquez Mota, the contender for Calderon’s PAN, said she brought up the need for both countries to improve the fight against money laundering.

“I told him that I will neither make a truce nor surrender in the fight against organized crime because for me the most important things is the security of all families,” she said.

Lopez Obrador said that in his meeting with Biden he suggested “a new bilateral relationship with the United States based on cooperation for development.”

“The problems with crime and lack of safety have their origins in the lack of welfare, and that is why it is very important that in bilateral relations, priority be given to development,” said Lopez Obrador, “so that there are jobs, welfare and we can put the country on the right track and be able to decrease migration.”

Biden paid a visit to the Basilica of Our Lady of Guadalupe, considered one of the most visited sanctuaries in the Roman Catholic faith. He kneeled, prayed and crossed himself before walking out of the church.

“My mother was a great devotee of the blessed mother,” said Biden, a Catholic. “I would have come if there were nothing but this,” he said referring to the basilica.

At a meeting earlier in the day, Calderon asked Biden for Washington to do more to halt the flow of weapons and drug money into Mexico.

Mexico’s president “repeated the urgent need to strengthen actions against the trafficking of weapons into our country and money laundering,” his office said in a statement.

Biden said that even in the absence of an assault rifle ban, President Barack Obama’s administration was doing as much as it could to stop the flow of arms by conducting inspections of border checkpoints and requiring reporting of multiple sales of large weapons.

Biden’s trip takes place amid unprecedented pressure from political and business leaders to talk about decriminalizing drugs. The presidents of Costa Rica, Guatemala, El Salvador, Colombia and Mexico have said in recent weeks they’d like to open up the discussion of legalizing drugs.

“It is a totally legitimate debate and it’s worth debating in order to lay to rest some of the myths that are associated with the notion of legalization,” Biden said. “The debate always occurs, understandably, in the context of serious violence that occurs with the society, particularly in societies that don’t have the institutional framework and the structure to deal with organized, illicit operations.”

The vice president said, however, that legalization would be unworkable “unless you are going to not only legalize but you are going to provide a government apertures for the distribution of the drugs.”